Add bindings for zend_llist

Author: joehoyle

src/zend/linked_list.rs

@@ -0,0 +1,46 @@
+use std::marker::PhantomData;
+
+use crate::ffi::{zend_llist, zend_llist_element, zend_llist_get_next_ex};
+
+pub type ZendLinkedList = zend_llist;
+
+impl ZendLinkedList {
+    pub fn iter<T>(&self) -> ZendLinkedListIterator<T> {
+        ZendLinkedListIterator::new(self)
+    }
+}
+
+pub struct ZendLinkedListIterator<'a, T> {
+    list: &'a zend_llist,
+    position: *mut zend_llist_element,
+    _marker: PhantomData<T>,
+}
+
+impl<'a, T> ZendLinkedListIterator<'a, T> {
+    fn new(list: &'a ZendLinkedList) -> Self {
+        ZendLinkedListIterator {
+            list,
+            position: list.head,
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl<'a, T: 'a> Iterator for ZendLinkedListIterator<'a, T> {
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.position.is_null() {
+            return None;
+        }
+        let ptr = unsafe { (&mut *self.position).data.as_mut_ptr() };
+        let value = unsafe { &*(ptr as *const T as *mut T) };
+        unsafe {
+            zend_llist_get_next_ex(
+                self.list as *const ZendLinkedList as *mut ZendLinkedList,
+                &mut self.position,
+            )
+        };
+        Some(value)
+    }
+}